First, create a backup of the shop and its database.
To update DHL Shipping 1.x to version 2.x, go into the Magento base directory and execute these commands:
composer require --update-with-all-dependencies dhl/shipping-m2:^2.0.0 php bin/magento setup:upgrade php bin/magento cache:flush php bin/magento setup:di:compile php bin/magento setup:static-content:deploy <List of locales>
Replace the part <List of locales> with the localizations used in your shop, e.g. "de_DE en_US en_GB" etc.
After the update
Verify that the DHL module still works as expected.
Also note the hints in the documentation chapter "Migration from DHL Shipping Version 1".
The order of the configuration options has changed during the update from version 1.x to version 2. Please check that the following settings are still configured correctly:
- Stores → Configuration → Sales → Shipping Settings
- Stores → Configuration → Sales → Post & DHL Shipping